Lamp socket for photoflash unit



Aug. 17, 1965 'c. G. VROOM 3,201,741

LAMP SOCKET FOR PHOTOFLASH UNIT Filed Dec. 5, 1962 Fig. 2

CLIFFORD 6. VROOM IN VEN TOR.

ATTORNEYS United States Patent 331M541 LAMP SQNIKET ENE Ciiiford G. Vroom, Rochester, NIL, assignor to Eastman Kodak Company, Rochester, N.Y., a corporation of New Jerse Filed Dec. 3, 1962, Ser. No. 241,626 7 (Ilaims. (til. 339-45) The present invention relates to a photoflash unit for use in combination with photographic cameras, and particularly to an improved lamp socket for such unit which is adapted to accommodate midget flash lamps of the type designated as AG-l.

Flash units having sockets capable of accommodating AG-l type flash lamps are generally well known, but they have possessed certain disadvantages. One of these has been the inability to securely hold the lamp in a socket in a stable and upright condition. This difliculty has generally been due to the fact that this type of lamp has a peculiar flattened base formed as a part of the lamp globe and which provides little or no contiguous surface on a lamp base which the socket might engage to accurately locate and stabflize the lamp in a given axial position. Furthermore, the peculiar shape of the base of these lamps makes it diflicult to provide a laching means for positively holding the lamps in the socket, and the conventionally used frictional grip provided by the socket contacts has been opposed by a spring loaded lamp ejecting means so that such arrangements have not been too satisfactory with known socket constructions.

The primary object of the present invention is to provide a lamp socket for AG-l type flash lamps into which the lamp is inserted sideways from the front rather than axially from the top as is usually the case. This permits the use of a novel arrangement of socket contacts and other lamp-base engaging means which will accurately hold the lamp in a stabilized and accurate position in the socket.

A further object is to provide a lamp socket for AG-l type lamps which has a spring loaded lamp ejector and a selectively releasable latch means for positively latching the lamp in the socket against the action of said ejector.

And yet, another object is to provide a lamp socket of the type set forth in which the latch means, the release therefor and one socket contact are formed as integral parts from a single piece of metal, the contact being so formed that it is flexible and capable of movement relative to the latch means to assure good electrical contact between itself and one of the lamp terminals regardless of the size, shape or position of the terminal on the lamp base.

And still another object is to provide a flash lamp socket of the type set forth which requires a minimum number of parts and is very easy to assemble. One reason for this is that the lamp ejector is a spring loaded double ended lever pivoted intermediate its ends by a V-notch in one edge thereof engaging a stationary rib in the socket housing, the rib and V-notch cooperating in such a way that the spring acting on the ejector holds this part in assembled relation rather than tending to separate it from the rib.

The novel features that I consider characteristic of my invention are set forth With particularity in the appended claims. The invention itself, however, both as to its organization and to its method of operation, together with additional objects and advantages thereof are best understood from the following description when read in connection with the accompanying drawings in which:

FIG. 1 is a partial front view of a photoflash unit incorporating a lamp socket constructed in accordance with a preferred embodiment of the present invention, and with the front wall of the lower portion of the unit broken ice away to show the socket construction as well as the power supply for the unit,

FIG. 2 is a horizontal sectional View taken substantially on line 22 of FIG. 1,

FIG. 3 is a vertical sectional view taken substantially on line 33 of FIG. 1, and showing how the latch means positively engages one of the lamp terminals to hold a lamp in the socket,

FIG. 4 is a vertical sectional view taken substantially on line i4 of FIG. 1, and showing the lamp ejector in its normal lamp ejecting position in full lines and its tensioned position in dotted lines,

FIG. 5 is a perspective view of the one part which is formed up to comprise one socket contact, the lamp latching means and the release for the latch means, and

FIG. 6 is a side elevational view of a convention AG-l type flash lamp which the present socket is adapted to accommodate.

Since the lamp socket of the present invention has been designed particularly to accommodate AG-l type flash lamps, a knowledge of the configuration of the base portion of such lamps is deemed essential to a complete understanding of the present invention. Accordingly, while I have shown and will describe the configuration of the AG-l lamp I will not go into the terminal construction or manufacturing technique used in the production of this lamp. Such information can be obtained from US. Patent No. 2,982,119 which relates to this particular type of flash lamp.

Referring to FIG. 6, the AG-l flash lamp comprises a sealed glass envelope or globe 10 approximately of tubular shape and consisting of a short length of drawn tubing closed at one end by an integral flattened stem press or base 12 which is elongate transversely of the axis of the lamp and has a rounded bottom as shown at 14. The front and back sides of the stem press or base 12 are formed as flat surfaces preferably disposed substantially parallel to each other and to the axis of the lamp. The flat surfaces of the base are each provided with a transversely extending groove 18 for sliding engagement with co-operating guide track means of a lamp holding magazine or feeding chamber of a flash unit. Sealed in the base of the lamp is an ignition mount 29 comprising a pair of lead-in wires 21 which, in the manufacture of the lamp, are sealed into the base of the lamp so as to extend therethrough and into the globe of the lamp in a direction approximately longitudinally of the lamp in a more or less side-by-side spaced relation. Outwardly of the lamp base the lead-in wires are provided with suitable terminals comprising open-ended wire loops 22 respectively bent in opposite directions around the rounded end of the lamp base to extend upwardly along side opposite flat surfaces thereof but terminating short of groove 18 therein.

Having described the particular type of flash lamp which the socket of the present invention is designed to accommodate, the construction of this socket will now be described. The socket may be incorporated in a photoflash unit, indicated generally at 24, and which may comprise a housing molded from a suitable plastic material. The upper end of the housing has a concave front wall 26 to which a concave reflector 28 is attached m any suitable manner, i.e. cement, and the lower end of the housing comprises a supporting block 29 the top Wall 39 of which is horizontal and joins the reflector while the adioining front wall 31 of which is vertical and is provided with a suitable irregularly shaped cavity 32 adapted to house the battery power supply and house and support the socket contacts and circuit connections therefrom to the power supply as will be hereinafter described. The cavity 32 is open at the bottom of the housing for permitting insertion of the batteries, and is adapted to be closed by a cover a narrow elongated recess 46 which opens through the a top wall 3% of the block. This elongated recess extends vertically from'the top wall 36 to that portion of the cavity 32 which receives two dry cell batteries B of the miniature type in side-by-side relation. This recess is slightly wider than the thicknessof the flatttened base 12 'of the lamp'so that the lamp can only he slid into the recess in a certain orientation, namely with the narrow end of the base leading. When the, lamp is slid into the recess in this manner, the globe of the lamp extends above the top wallfifl of the supporting block and in front of the reflector and the tapered walls of the globe 1t) engage the corners of the recess at the top wallto determine the depth at which the lamp terminals extend vertically into the'recess, see FIGS. 3 and 4. It necessarily follows that the upper edge of the coverplate 36 is cut away, as indicated at 42, 'in alignment with the upper end of the recess 4% to allow the base of the lamp to be inserted sidewise into, and retracted from, the recess. It will appear that this elongated recess opens up into the aforementioned cavity '32 at certain points to allow for the necessary circuit leads from the socket contacts'to thebatteries, but it 'is the elongatedrecess portion of the cavity which'is esmetal contact strap 50 the upper end 52 of which is 10- cated so as to frictionally'engage oneof the lamp terminals 22 when the lamp is inserted into'the socket and thereby to constitute one of the socket contacts, see FIG.

Extending vertically of, and lying against, the -right side, looking at FIG; 1, of the. elongated recess 40 is a first n5 4. .As most clearly shown in FIGS. 1 and 2, the front or' 40 leading edge ofthe socket contact 52is turned outwardly fromthe edge of the recess and lies in a depression 54 in the front wall of the supporting block, which by the way can open into andrthereby form a part of the aforementioned cavity 32. It will be obvious that turning back the leading edge of the socket contact 52 in this manner overcomes any difficultyin loading a lamp into the socket which might be encountered werethe leading edge of this socket contact left straight so that it might be engaged by 'the'batteries, the contact strap includes a supporting one of the' lamp terminals 22 as the lamp is inserted into 5 the socket. As is shown in FIG. 1, as a means of supportportion 57 lying in perpendicular relation to the contact 5 properand which rests upon, and is fastened to, a boss 58 in the'cavity by a self-tapping screw 59. A contact strap 60 lying in a plane in perpendicular relation to supporting portion 57 extends vertically downwardfto that portion of" the "cavity containing the batteries and whereonc end thereof resiliently engages the terminal of one battery when; inserted into the cavity. To this contact one lead of a conductive cord C is soldered,said cord having a connectionon the other end, not shown, for connecting'the" flash switch of a camera shutter in controlling relation with the lamp circuit of the flash unit in a known manner. A part Pof the'shape best shown in FIG. 5 is formed up -from.a single piece of resilient sheet metal and constitutes the second socket contact, a latch for positively as means for mounting these respective elements in proper operative relation in the flash unit and connecting the serves as the means for latching the lamp in the socket but also forms a part of the second socket contact as will be described. The flag member 72 which is connected to part P by a narrow strap 73 to make it more flexible than arm 71 serves as the primary second socket contact and, along with latch member?) provides double assurance of frictional mating of at least one of the socket contacts and/or 72) with one of the lamp terminals 22 regardless of size, shape or position of said terminals which may vary from lamp to lamp. Extending from the rear edge of part P and lying in a plane at right angles to the arm 71 thereof, is a lamp ejectingarm 75 which extends up the back of the flash unit when part P is mounted in the cavity 32 and/or elongated recess 40. -While this ejecting arm 75 could extend upwardly completely outside of the back wall of the flash unit, in order to improve the appearance of the unit and prevent accidental operation of the lamp ejecting arm, I have provided the back wall of the housing with a shallow recess 76 within which the ejecting arm lies and have provided the rear corner of the housing with an arcuate cutout or depression 80, see FIG. 2, which gives access to the upper end of the arm 7 so that tie operator can depress itwith his finger in the adjoining vertical and horizontal faces of an upstanding boss 33 in the cavity to locate the latch 749 and socket contact 72 adjacent the other side wall of the elongated recess ll opposite socket contact 52 and in which position these parts will frictionally engage the other terminal of a lamp as it is inserted into the socket. Thepart P is held in position in the recess by a self-tapping screw 84 passing through hole 84' in vertical mounting portion 31.

' To aidin locating part P and prevent rotation thereof an inclined edge 85 on vertical mounting portion Sllabuts an upstanding lug 86 in the cavity 32. The part P is so formed and/or mounted in the elongated recess 40 that the'contacts 7t and 72 forming a part thereof are spaced from the othersocket contact 52 by a distance less than the thickness of the flattened base 12 of the lamp or the dimension between the outside edges of the two lamp terminals 22. Thus, when the lamp base is slid into-the socket between said contacts it must spread the two apart. To facilitate the insertion of'the lamp into the socket the leading edge of latch member 79 is turned outwardly as shown at 87 like theleading edge of contact 52 so that the 7 leading edges of these two parts form a trough into which the lamp base may be easily inserted, see FIG. 2. Part P also includes a contact strap S the turned-down end of which resiliently engages the'opposing terminal of the other battery and thereby connects the latch member 70 and second socket contact72 into the power circuit. The second lead of cord C is soldered to. this contact strap. A resilient contact strap 15% fixed t0 the wall of the cavity 32 is adapted to'bridge the opposing contacts of the two batteries B and complete the circuit for the flash unit whereby the two socket contacts are connected in series with the batteries.

.fully seated in the socket, the terminal 22 engaging socket contact 72 will drop behind the vertical edge 88 of latch 5 member 79 so that the lamp will be positively latched in 1 the socket. Accordingly, it will be appreciated that ele- -ment 70 serves not only as a contact to electrically connect' the lamp into the circuit' but also serves as a latch member for positively holding it in the socket. Primary latching a lamp in the socket, 'means for releasing said latch to free the lamp for ejection from the socket, as well socket contact 72 being more flexible than arm 71 of latch member 70,. and being capable of moving transversely relative to latch memberlti, assures'a good frictional electrical contact with the lamp terminal and allows the edge of the engaged terminal to drop behind the edge 88 of latch v'70. T 0 release the lamp from the socket, the operator merely presses on the turned-over end 9!) of the ejecting arm 75 to move it in the direction of the arrow 91. This causes the vertical arm 71 to be flexed in a direction away from the socket contact 52 and remove the edge 88 of the latch member '70 from in front of the lamp terminal engaged thereby. At this time, if the lamp is acted on by a spring loaded ejector of the type to be described hereinafter, the lamp will be forcibly ejected from the socket. When the ejector arm 75 is released, it and the latch member 70 will return to the normal latching position by reason of the resiliency of the arm 71 carrying the latch member 7 0.

The lamp ejector mechanism used in the present socket is most clearly shown in FIG. 4, and comprises a doubleended lever 92 which is preferably made from a plastic or other insulating material. This lever is provided intermediate its ends with a circular reinforced portion 93 provided at its rear edge with a substantially V-shaped notch 94 engaging the edge 95 of an upstanding rib 96 in the cavity 32 which extends transversely of the elongated recess 40. The lower end 97 of the lever 92 is normally acted upon by a leaf spring 98 to be pivoted in a clockwise direction to its ejecting position, shown in full lines in FIG. 4, while the other end 99 of the lever, which lies in the elongated recess between the socket contacts to be engaged by the lamp base, is moved to the front of the socket where it kicks the lamp from the socket. As a lamp is inserted into the socket, the base 12 thereof engages the end 99 of the ejector lever 92 and forces it to the dotted line position while the other end of this lever tensions the spring 98. The lamp ejecting mechanism will be held in a cocked condition with the lamp in the socket when the rear edge 88 of the lamp member 70 drops in front of the lamp terminal 22 it engages. When the latch is released by depressing ejector arm 75 in the direction of arrow 91, the lamp base will be released and the ejecting mechanism will forcibly kick the lamp from the socket.

While any suitable form of spring arrangement may be provided to act on the end 97 of ejector lever 92, I have found that a particularly suitable arrangement comprises turning the spring up from a spring metal plate 100 which can extend across the lower end of the elongated recess 40 and be fastened in the cavity 32 by the same screw 84 which is used to fasten part I in the cavity 32 along with another self-tapping screw 101 engaging a boss in the cavity. Looking at FIG. 4, it will be seen that the V- notch 94 in lever 92 is so formed that when the lever is in its lamp ejecting position, the full line position of FIG. 4, the lower face of the notch engages the underside of the upstanding rib 95 to positively limit the pivotal movement of the lever in this position. Likewise, counterclockwise movement of the ejecting lever 92 by insertion of the lamp into the socket is positively limited when the upper face of the notch engages the upper surface of the rib 96, see dotted line position in lever of FIG. 4, and at which time the lamp is properly inserted in the socket. It will be observed that this arrangement of parts ensures that the ejecting lever 92 cannot become disassembled from its fulcrum arrangement with the rib 96 so long as spring 98 is acting on the end 97 thereof at a point spaced from the rib 96. In the present arrangement, however, accidental disassembly of the V-notch from engagement with the end of the rib 96 is further prevented by virtue of the fact that plate ltltl from which spring 98 is formed lies in front of and engages the reinforced circular portion of the lever opposite the V -notch therein.

While I have shown the combined socket contact and latch member, along with the release '75 for the latch member and the primary socket contact 72, all formed from a single piece of spring metal so that they can be assembled into the flash unit as a single unit, the present invention is not limited to such an arrangement. Each of these parts could just as well be formed as individual elements and mounted in the flash unit separately without going beyond the spirit of the present invention. Likewise, the manner in which the socket contacts are connected into a circuit controllable by the flash synchronizing switch of the camera, and which the circuit provides for readily insertion, or removal, of batteries therefrom is not important to the present invention because this lamp socket could form a part of a flash unit which is built into a camera rather than forming a part separate from the camera.

Although I have shown and described certain specific embodiments of my invention, I am fully aware that many modifications thereof are possible. My invention therefore is not to be limited to the precise details of construction shown and described, but is intended to cover all modifications coming within the scope of the appended claims.

I claim:

1. A lamp socket for releasably retaining a flash lamp having a globe portion tapering to a flattened base, a first electrical terminal extending from one side of said base and a second electrical terminal extending from the other side of said base, said socket comprising in combination:

(A) a supporting block having adjoining side and top walls in substantially right angular relation,

(1) said side wall provided with an elongated recess opening into said top wall and into which recess the flattened base of said lamp is adapted to be inserted sidewise with said electrical terminals facing opposing walls of said recess with the globe portion extending above said top wall and with the tapered portion of said globe engaging the corners joining the opposing walls of said recess and said top wall to support the lamp in an upright position in said recess and to define its axial position therein,

(B) first and second electrical contacts respectively located in said recess adjacent opposite sides thereof and spaced apart by a distance such that each contact is adapted to frictionally engage opposite ones of said electrical terminals on said lamp when it is inserted into said recess,

(C) a spring loaded lamp ejector mounted in said recess to be engaged and moved from a normal lamp ejecting position to a tensioned position by the base of a lamp when it is inserted sidewise into said recess,

(D) a latch member at one side of said recess and movable between a normal latching position, wherein it positively engages one of said lamp terminals when a lamp is inserted into said recess to hold the lamp in said recess against the tension of said ejector member, and a release position, wherein it frees said terminal and allows the ejector member to eject the lamp from said recess, and

(E) means remote from said recess and accessible from outside of said supporting block for selectively and positively moving said latch member to its release position.

2. A lamp socket according to claim 1, in which at least one of said electrical contacts is normally urged toward the opposing electrical contact to squeeze the lamp base inserted between them and thus insure good electrical contact between said contacts and said lamp terminals.

3. A lamp socket according to claim 2 in which the edge of each of said contacts facing the open side of said recess is inclined in opposite directions to facilitate insertion of said lamp base into said recess and between said contacts.

4. A lamp socket according to claim 1, in which said supporting block is made from an insulating material, and in which one of said electrical contacts, said latch member and the means for selectively moving said latch member to its release position are formed from one piece of metal and each of said last-mentioned electrical contact and latch member engage the same lamp terminal.

5. A lamp socket for releasably retaining a flash lamp having a globe portion tapering to a flattened base, a first electrical terminal extending from one side of said base and a second electrical terminal extending from the other side of said base, said socket comprising in combination:

(A) a supporting block having adjoining side and top walls in substantially right angular relation,

(1) said side wall provided with an elongated recess opening into said top wall and into which recess the flattened base of said lamp is adapted to be inserted sidewise with said electrical terrninals facing opposing Walls of said recess with the globe portion extending above said top wall,

(B) first and second electrical contacts respectively located in said recess adjacent opposite sides thereof and spaced apart by a distance such that each contact is adapted to frictionally engage opposite ones of said electrical terminals on said lamp when it is inserted into said recess,

(C) a spring loaded lamp ejector mounted in said recess to be engaged and moved from a normal lamp ejecting position to a tensioned position by the base of a lamp when it is inserted sidewise into said recess, and comprising a double-ended lever pivoted intermediate its ends about an axis located below and extending substantially at right angles to the flattened base of a lamp when inserated into said recess, one end of said lever located in said recess to engage one end of the lamp base as it is inserted into said recess, and a spring acting on the other end of said notch in the edge of said double ended lever is so formed that a portion of the edge thereof extending below said rib engages the bottom wall of said rib to positively limit rotation of said lever when said lever reaches its lamp ejecting position whereby said spring acting'on said lever serves to hold the notch in said lever in fulcrum relation with said upstanding rib.

References Cited by the Examiner UNITED STATES PATENTS 2,984,810 5/61 KaWate 339144 X 3,079,490 2/ 63 Barbieri 339 X 3,118,613 1/64 Irwin 33945 X 3,120,417 2/64 Francis 339-45 X JOSEPH D. SEERS, Primary Examiner. w. DONALD MILLER, Examiner. 

5. A LAMP SOCKET FOR RELEASABLY RETAINING A FLASH LAMP HAVING A GLOBE PORTION TAPERING TO A FLATTENED BASE, A FIRST ELECTRICAL TERMINAL EXTENDING FROM ONE SIDE OF SAID BASE AND A SECOND ELECTRICAL TERMINAL EXTENDING FROM THE OTHER SIDE OF SAID BASE, SAID SOCKET COMPRISING IN COMBINATION: (A) A SUPPORTING BLOCK HAVING ADJOINING SIDE AND TOP WALLS IN SUBSTANTIALLY RIGHT ANGULAR RELATION, (1) SAID SIDE WALL PROVIDED WITH AN ELONGATED RECESS OPENING INTO SAID TOP WALL AND INTO WHICH RECESS THE FLATTENED BASE OF SAID LAMP IS ADAPTTED TO BE INSERTED SIDEWISE WITH SAID ELECTRICAL TERMINALS FACING OPPOSING WALLS OF SAID RECESS WITH THE GLOBE PORTION EXTENDING ABOVE SAID TOP WALL, (B) FIRST AND SECOND ELECTRICAL CONTACTS RESPECTIVELY LOCATED IN SAID RECESS ADJACENT OPPOSITE SIDES THEREOF AND SPACED APART BY A DISTANCE SUCH THAT EACH CONTACT IS ADAPTED TO FRICTIONALLY ENGAGE OPPOSITE ONES OF SAID ELECTRICAL TERMINALS ON SAID LAMP WHEN IT IS INSERTED INTO SAID RECESS, (C) A SPRING LOADED LAMP EJECTOR MOUNTED IN SAID RECESS TO BE ENGAGED AND MOVED FROM A NORMAL LAMP EJECTING POSITION TO A TENSIONED POSITION BY THE BASE OF A LAMP WHEN IT IS INSERTED SIDEWISE INTO SAID RECESS, AND COMPRISING A DOUBLE-ENDED LEVER PIVOTED INTERMEDIATE ITS ENDS ABOUT AN AXIS LOCATED BELOW AND EXTENDING SUBSTANTIALLY AT RIGHT ANGLES TO THE FLATTENED BASE OF A LAMP WHEN INSERATED INTO SAID RECESS, ONE END OF SAID LEVER LOCATED IN SAID RECESS TO ENGAGE ONE END OF THE LAMP BASE AS IT IS INSERTED INTO SAID RECESS, AND A SPRING ACTING ON THE OTHER END OF SAID LEVER TO NORMALLY URGE THE LEVER TO THE LAMP EJECTING POSITION. 